Scombroid

Background

• Caused by eating fish which have been improperly stored/refrigerated
  • Bacteria grow and produce heat-stable toxin that causes histamine release when consumed
  • Patient may complain that the fish tasted like pepper, metallic, or bitter
• Frequently misdiagnosed as seafood allergy

Causes

Ingestion of:

• Fish
  • Tuna
  • Bluefish
  • Mahi-mahi
  • Herring
  • Mackerel
  • Skip-jack
  • Sardine
  • Bonito
• Swiss cheese (contaminated)

Clinical Features

• Symptoms generally start within one hour of ingestion, and usually resolves within 12 hours (if untreated)
• Flushing, warmth, erythematous and urticarial rash, palpitations, dizziness, diarrhea, perioral burning, itching, or edema
• May also see severe throbbing headache, blurred vision, tachycardia, and respiratory distress

Differential Diagnosis

• Ciguatera - similar clinical presentation, different fish

Acute allergic reaction

• Allergic reaction/urticaria
• Anaphylaxis
• Angioedema
• Anxiety attack
• Asthma exacerbation
• Carcinoid syndrome
• Cold urticaria
• Contrast induced allergic reaction
• Scombroid
• Shock
• Transfusion reaction

Erythematous rash

• Positive Nikolsky’s sign
  • Febrile
    • Staphylococcal scalded skin syndrome (children)
    • Toxic epidermal necrolysis/SJS (adults)
  • Afebrile
    • Toxic epidermal necrolysis
• Negative Nikolsky’s sign
  • Febrile
    • Toxic shock syndrome
    • Kawasaki disease
    • Scarlet fever
    • DRESS syndrome
    • Cellulitis
    • Acute generalized exanthematous pustulosis
  • Afebrile
    • Alcohol intoxication
    • Anaphylaxis
    • Cellulitis
    • Dermatitis (multiple types)
    • Drug rash
    • Erysipelas
    • Erythema multiforme
    • Exfoliative erythroderma
    • Scombroid
    • Vancomycin infusion reaction

Evaluation

• Generally clinical diagnosis

Management

• Antihistamines - give both H1 and H2 antagonists
• Consider epinephrine, albuterol if symptoms of respiratory distress

Disposition

• Generally may be discharged

See Also

• Marine toxins and envenomations